Leases (Tables)

9 Months Ended

Sep. 30, 2020

Leases [Abstract]

Schedule of balance sheet impact of leases

For lease agreements entered into or reassessed after the adoption of the new leases standard, we combine lease and nonlease components.

Classification	September 30, 2020		December 31, 2019
	(dollars in thousands)
Right-of-Use Assets—Finance leases
Right-of-use assets	$	302,732	$	302,732
Less: Accumulated provision for depreciation	(261,457)		(257,504)
Total finance lease assets	$	41,275	$	45,228
Lease liabilities—Finance leases
Obligations under finance leases	$	72,354	$	75,649
Long-term debt and finance leases due within one year	6,418		6,081
Total finance lease liabilities	$	78,772	$	81,730

Classification	September 30, 2020		December 31, 2019
	(dollars in thousands)
Right-of-Use Assets—Operating leases
Electric plant in service	$	3,550	$	3,237
Total operating lease assets	$	3,550	$	3,237
Lease liabilities—Operating leases
Capitalization—Other	$	2,553	$	2,293
Other current liabilities	1,010		1,252
Total operating lease liabilities	$	3,563	$	3,545

Schedule of lease cost

		Three months ended				Nine months ended
Lease Cost	Classification	September 30, 2020		September 30, 2019		September 30, 2020		September 30, 2019
		(dollars in thousands)
Finance lease cost:
Amortization of leased assets	Depreciation and amortization	$	1,344	$	1,189	$	4,032	$	3,567
Interest on lease liabilities	Interest expense	2,217		2,372		6,651		7,116
Operating lease cost:	Inventory(1) & production expense	286		542		1,081		2,308
Total leased cost		$	3,847	$	4,103	$	11,764	$	12,991

(1) The majority of our operating lease costs relates to our railcar leases and such costs are added to the cost of our fossil-fuel inventories and are recognized in fuel expense as the inventories are consumed.

Summary of lease terms and discount rates

	September 30, 2020		December 31, 2019
Lease Term and Discount Rate:
Weighted-average remaining lease term (in years)
Finance leases	8.10		8.84
Operating leases	7.39		7.39
Weighted-average discount rate:
Finance leases	11.05	%	11.05	%
Operating leases	4.66	%	5.12	%

Schedule of cash paid for amounts included in the measurement of lease liabilities

	Nine months ended
	September 30, 2020		September 30, 2019
	(dollars in thousands)
Other Information:
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from finance leases	$	4,516	$	4,817
Operating cash flows from operating leases	$	1,301	$	2,602
Financing cash flows from finance leases	$	2,959	$	2,658
Right-of-use assets obtained in exchange for new operating lease liabilities	$	—	$	6,983

Schedule of maturities of finance and operating lease liabilities

Maturity analysis of our finance and operating lease liabilities as of September 30, 2020 is as follows:

	(dollars in thousands)
Year Ending December 31,	Finance Leases		Operating Leases		Total
2020	$	7,475	$	261	$	7,736
2021	14,949		1,119		16,068
2022	14,949		929		15,878
2023	14,949		708		15,657
2024	14,949		234		15,183
Thereafter	55,532		1,085		56,617
Total lease payments	$	122,803	$	4,336	$	127,139
Less: imputed interest	(44,031)		(773)		(44,804)
Present value of lease liabilities	$	78,772	$	3,563	$	82,335

Schedule of lessor's income from leases

Lease income recognized during the three and nine months ended September 30, 2020 and September 30, 2019 was as follows:

	Three Months Ended September 30,				Nine months ended September 30,
	2020		2019		2020		2019
	(dollars in thousands)
Lease income	$	1,543	$	1,514	$	4,633	$	4,554